This slot can be reimplemented by the decoration to return
the regions defined by KDecorationDefines::Region.
The only region defined initially is ExtendedBorderRegion.
This region specifies an invisible input region that can extend
both inside and outside the decoration.
The intended use case is to be able to have an active border
area that's larger than the visible borders.
The KDecoration library lives in libkdecorations/ now.
Installation pathes are unchanged, so this does not influence 3rd party
decorations.
The changes in the KWin main directory are required due to incorrect
includes.
CCMAIL: kwin@kde.org
